Por que o smartmontools não pode desativar o SMART check?

Quando uso smartctl -s off /dev/sdacom privilégio de administrador, o suporte SMART é desativado:

C:\Program Files\smartmontools\bin>smartctl -s off /dev/sda
smartctl 6.5 2016-05-07 r4318 [i686-w64-mingw32-win8.1] (sf-6.5-1)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF ENABLE/DISABLE COMMANDS SECTION ===
SMART Disabled. Use option -s with argument 'on' to enable it.

É confirmado usando smartctl -a /dev/sda/:

C:\Program Files\smartmontools\bin>smartctl -a /dev/sda
smartctl 6.5 2016-05-07 r4318 [i686-w64-mingw32-win8.1] (sf-6.5-1)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Hitachi/HGST Travelstar Z5K320
Device Model:     Hitachi HTS543232A7A384
Serial Number:    E2034243EEG7TP
LU WWN Device Id: 5 000cca 690e24d54
Firmware Version: ES2OA60W
User Capacity:    320,072,933,376 bytes [320 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    5400 rpm
Form Factor:      2.5 inches
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ATA8-ACS T13/1699-D revision 6
SATA Version is:  SATA 2.6, 3.0 Gb/s
Local Time is:    Tue Jan 17 23:10:55 2017 SEAST
SMART support is: Available - device has SMART capability.
SMART support is: Disabled

SMART Disabled. Use option -s with argument 'on' to enable it.

Mas quando eu reinicio meu computador, a verificação SMART volta novamente. Por que é que?

Minha versão do BIOS é 1.31 e não há nenhuma opção SMART nela (apenas recuperação do D2D).